Brick grab



J. P. CALLAGHAN Aug. 22, 1939.

BRICK GRAB 3 Sheets-Sheet L y Filed Jan. 26 1938 lllllll l'l l l Q R2 ng] INVENTOR m LLJJL RNEYS .jzhnficallagham BY WW? ATTO 19394 J. P.CALLAGHAN I 2,170,706

mucx GRAB I Filed Jan. 26, 19 8 s Sheets-Sheet 2 Lyynmgssss j; P C lIZVENTOR 4 r o a 6 BY ATTORNEYS Aug. 22, 1939.

J. P. CALLAGHAN BRICK GRAB Filed Jan. 26,. 1938 5 Sheets-Sheet 3 SSESVYITNE INVENTOR JO/IHR CaZZaghan BY M W AITSlZNEYfi Patented Aug. 22,1939 UNITED STATES PATENT OFFKIE BRICK GRAB Application January 26,1938, Serial No. 186,971

Claims.

This invention relates to improvements in grabs or lifters and hasparticular relation to apparatus of the character to be used in liftingpiles of bricks, stones and the like.

It is an object of the invention to provide an improved brick grab ofsimple, sturdy construction which will operate in an efiicient mannerover a long period of time with comparative freedom from wear.

A further object of the invention is the provision of an improved grabof the above character having improved operating leverage and linkagebetween the gripping jaws and lifting head and also having improvedguide mechanism and locking means whereby the jaws may be locked in openposition.

For a fuller understanding of the invention reference should be had tothe accompanying drawings in which Fig. 1 is a front elevation of abrick grab embodying my invention;

Fig. 2 is a side elevation of the brick grab;

Fig. 3 is a plan view;

Fig. 4 is a detailed view showing the construction of one of thegrippingv buttons and of the lower end of the shield plate employed onthe gripping jaws;

Fig. 5 is a rear view of one of the bell cranks used in the grippingjaws;

Fig. 6 is a side view of the bell crank; and

Fig. '7 is a plan view from the lower side thereof of the lockingmechanismfor retaining the gripping jaws in open position.

My improved grab comprises a pair of jaws indicated generally at 8, forgripping a pile of bricks or other articles, and a lifting headindicated by the numeral 9 for lifting the grab and also for controllingthe operation of the jaws. The gripping jaws are connected to thelifting head by a series of levers and links so as to provide for a highefiiciency in operation, and when the lifting head is shifted away fromthe jaws they are caused to close and grip the articles which are to belifted, and likewise, when the lifting head is shifted towards the jawsthey are caused to open and release the articles.

The grab is provided with a frame 10 which is generally rectangular inplan and on which the gripping jaws and. operating levers and linkageare mounted. The gripping jaws preferably comprise two pairs ofconfronting bell cranks II which are spaced apart as shown and pivotallymounted on the shafts I2 adjacent the four corners of the frame It. Eachof the bell crank levers is formed. of a downwardly extending bifurcatedarm 14 which serves as the gripping portion of the jaw, and also ahorizontal arm l5 whereby the bell crank is pivoted to shift the jawstowards and away from each other.

The arms 15 are relatively long so as to provide for maximum leverageand extend from the pivotal points 2 to adjacent the opposite side ofthe frame as shown. To prevent interference between the arms 15 of theconfronting bell cranks it will be appreciated that they must bearranged in staggered relation and for this purpose I prefer to formeach of the bell cranks with a spacing collar it on one side around thepiv otal point. In this way the bell cranks in each pair are spaced anequal distance apart but one of the pairs is offset with respect to theother, as most clearly shown in Fig. 3. It will be appreciated thatrelatively heavy loads are engaged and lifted by the gripping jaws andaccordingly they should be of relatively strong construction, and forthis purpose I prefer to form the downwardly depending arms M of thebell cranks of angle bars as shown. The lower, bifurcated ends of thearms in each pair of bell cranks are suitably connected together so asto form a unitary gripping jaw as by means of T-bars 16.

Usually the surface of a pile of bricks or similar articles isirregular, and also, it will be appreciated that in lifting a pileofbricks as. a unit a maximum amount of gripping pressure must beapplied to the lower rows of bricks upon which the superimposed bricksare supported. For this reason, adjacent the lower edge of the grippingjaws I provide confronting rows of yielding, inwardly projectinggripping buttons 18 positioned so that they will engage the lower row ofa pile of bricks. or other articles. and formed so that they willcompensate for any irregularities in the surface thereof, butnevertheless will apply sufficient gripping pressure so as to enable arelatively large and heavypile to be lifted by the grab. For thispurpose I form channels adjacent the lower edges of the gripping jaws asby securing angle bars I! to the T-bars as shown, in spaced relationfrom the bottom thereof. The gripping buttons are positioned in thechannels and each comprises a cap having depending ends 19 projectinginto the channel and having sliding engagement with the horizontalportions of the T-bar and angle bar which accordingly serve as guidesfor the buttons. Each of the gripping buttons is held in position by apin 28 secured in the cap and extending through and having looseengagement with the vertical portion of the T-bar IS. The outer end ofeach of the pins. 20

respective gripping jaws.

is provided with suitable means such as a cotter pin 2!, to prevent thebutton from escaping from the channel. To normally hold the button inextended position, spiral springs 22 are formed around the pins 20. Itwill be appreciated that since the grab is used to grip and liftarticles of considerable weight the springs 22 must be relatively strongand must exert considerable force upon the gripping buttons to urge theminto the extended position shown in Figs. 1 and 4. A continuous row ofconfronting buttons I8 is provided in each side of the gripping jaws.

I have found that it is desirable that the jaws should be provided withsmooth inner and outer surfaces so as not to dislodge any of the bricksor similar articles that are to be lifted by the grab and for thispurpose I encase each side of the jaw with shield plates 23 and 24. Theshield plates 23, which cover the outer surfaces of the jaws may beshaped to conform with the general contour of the depending arms M asshown most clearly in Fig. 2, and they are preferably rigidly secured inposition as by means of angle bars 25 and brackets 26.

The shield plates 24 on the inner faces of the gripping jaws areyieldingly held in position so that normally the lower ends thereof arespaced from their respective jaws so that they will shift towards thejaws when pressure is applied thereto. Thus, at their upper ends theplates 23 are connected by means of flexible strips 21 to brackets 28thereby permitting the lower portion of the shield plates to shiftrelative to the jaws. Adjacent their lower ends they are connected topins 29 which extend through the depending arms I4 and have slidingengagement therewith so that the lower portions may shift towards andaway from the arms. Suitable means such as the nuts 30 are provided atthe ends of the screws 29 so as to limit the outward movement of theshield plates, and spiral springs 3| are disposed around the pins so asto normally hold the shield plates 23 in spaced relation with regard totheir Due to the fact that the lower ends of the shield plates 23 areheld in positon by a relatively few number of pins 29 the combinedresistance of the springs 3| is not as great as the combined resistanceof the springs 22 which are disposed in the gripping buttons I8. As aresult of this structure, when the gripping jaws engage a pile of bricksor similar articles the shield plates 23 will yield and the burden ofgripping the pile of bricks rests primarily upon the gripping buttonsl8.

The operation of the gripping jaws is caused by shifting the arms l upand down so as to cause the arms M to shift towards and away from eachother. The shifting of the arms i5 is controlled by a series of linksand levers which are connected to the lifting head as shown. Thus, eachof the arms I5 is pivotally connected adjacent its end to a link 33which in turn is pivoted to a link 34 pivotally secured to a bracket 35.It will be seen that the links 33 and 34 correspond in number to thenumber of bell crank levers employed. Thus, in the present instance fourbell crank levers are employed and accordingly, four of each of thelinks 33 and 34 are likewise employed. Each of the links 34 shouldpreferably be positioned above the arm E5 to which it is connected atleast at the point of connection but at their inner ends they arepreferably offset towards each other so as to facilitate connection tothe head as shown in Fig. 3. The brackets 35 are pivotally mounted atthe four tures 5i and 52.

corners of the frame l0, adjacent to the shafts l2 as shown.

So as to obtain the maximum leverage the intermediate links 33 shouldpreferably be pivoted to the links 34 adjacent the brackets 35 while thefree ends of the links 34 are pivotally connected to links 38 which arepivoted to the two ends of the lifting head 9. The brackets 35 are freeto pivot towards and away from one another so as to permit the links 34to freely pivot from lowered to raised position. Adjacent the center ofthe lifting head a bail or loop 40 may be provided whereby the grab maybe suitably suspended.

A satisfactory lifting head is shown in the drawings and comprises abeam formed of a pair of spaced parallel plates 4| having aninterconnecting fin 42 adjacent the central portion thereof and a pairof cross rods or pins 43 adjacent the two ends thereof to which thelinks 38 are connected.

Due to the linkage and levers hereinbefore described, when the bail 40is raised upwardly the arms l4 will shift towards each other therebyclosing the gripping jaws 8. This is due tothe fact that the liftinghead raises the links 39, which in turn pivot the inner ends of thelinks 34 upwardly. The pivoting of links 34 upwardly through themovement of links 33 causes the arms l5 to pivot upwardly, with theresult that the depending arms [4 pivot towards each other. When thebail 40 is lowered to the position shown in. the drawings, the oppositeaction to that just described takes place, with the result that the armsl4 shift away from each other and the grip ping jaws 8 are in openposition.

So as to insure a uniform and equal action of the several links Iprovide a guide which causes the beam to move up and down in apredetermined manner. This guide takes the form of a tube. 44 which issecured adjacent its lower end to the frame i0, and a shaft 45positioned in the tube so as to slide telescopically therein andconnected at its upper end as by means of a pin 46 to the lifting head.Thus, as the beam moves towards and away from the frame its movement isguided by the shifting of shaft 45 in the tube 44. To prevent jammingand so as to obtain more eflicient operation the tube 44 and shaft 45are positioned in approximately the center of gravity of the grabbeneath the bail 46.

At times it is desirable to lock the jaws in open position so that thedevice may be lowered over the pile of bricks as shown in Fig. 1 withoutthe jaws closing, and for this purpose I provide improved lockingmechanism which is shown most clearly in Figs. 2 and 7. This lockingmechanism consists of an inverted channel bar 48 suitably securedbetween two sides of the frame of the grab. Adjacent the central portionof the channel bar a plate 49 is provided having a relatively enlargedopening 50 fitted around the tube 44 so as to permit the plate 49 toshift longitudinally relative to the tube 44.

The tube 44 is provided with a pair of aligned apertures 5| on oppositesides thereof adjacent the channel 48 and the shaft 45 is likewiseformed with an aperture 52 extending therethrough which is in alignmentwith the apertures 5| in the tube when the beam is in lowered positionand the jaws are opened as shown in Figs. 1 and 2. So as to lock thejaws in this position I provide suitable means such as a pin which maybe shifted so as to extend through the aper- This mechanism comprises apair of rods 53 and 54 extending in opposite directions from the plate49 through the channel 48. Each of the rods has an operating handle 55at the outer end thereof which are positioned on opposite sides of thegrab whereby the jaws may be locked in open position from either side ofthe grab. The rods are supported in the channel by brackets 55. Each ofthe rods is likewise secured to the plate 49 as by means of the pins Atits inner end the rod 54 is provided with an enlarged portion 58extending partially across the opening 563 in plate 49 and in alignmentwith the aperture 5| in tube 44. By shifting either of the handles 55 tothe left as viewed in Figs. 2 and '7 the member 58 can be extendedthrough the aligned apertures 5| and 52 to lock the jaws in openposition. To release the jaws the handles 55 are shifted to the right asviewed in these figures of the drawings. As a convenience and to aid inguiding the jaws as they are being lowered over the articles to beshifted handles 66 are connected to the depending arms l4 so as toproject outwardly beyond the shield plates 23.

In using the brick grab the jaws are locked in open position byprojecting the member 58 through the apertures 5| and 52 as heretoforedescribed. The jaws are then lowered over the article or articles to belifted, such as the pile of bricks indicated in dotted lines at Bl inFig. 1. Due to the shield plates 23 and 24 it will be appreciated thatthere are no projecting surfaces to engage or dislodge the bricks as thejaws are being lowered, both inner and outer faces of' the jawspresenting smooth, even surfaces. When the jaws have thus been lowered,the locking mechanism is released by shifting one of the handles 55 tothe right. The bail 40 is then lifted upwardly. The first result oflifting the bail upwardly is to close the jaws, due to the fact that thelifting head 9, levers 34, links 33 and arms l5 are all shifted orpivoted upwardly, causing the arms I 4 to pivot inwardly towards eachother.

Due to the arrangement of the levers and links as heretofore described amaximum amount of leverage is obtained with the result that the jawsexert considerable pressure against the pile of bricks or other articlesbeing lifted. The gripping buttons [8 engage and firmly grip the lowerrow of bricks and exert sufficient pressure so that the entire pile ofbricks may be supported in this manner. The continued raising of thebail 4!) thereafter causes the brick grab together with the pile ofbricks or other articles gripped between the jaws to be raised upwardly.The grab can thus be shifted to the desired position, where it islowered. After the pile of bricks and the grab rest upon the ground,continued lowering of the bail results in opening of the jaws to theposition shown in Fig. 1. The jaws can then be locked in open positionand the grab is again ready to be operated in the manner abovedescribed.

It will be appreciated that I have provided an improved brick grab ofsimple, sturdy construction, which is efficient in operation and whichmay be used over a long period of time with comparative freedom fromwear. It should be understood that while the device has been referred toas a brick grab it may be used for gripping and lifting other articles,and this name should not be interpreted as restricting the grab to thisparticular use. It should also be understood that modifications may bemade in the illustrated embodiment of the invention without departingfrom the invention as set forth in the accompanying claims.

I claim:

1. A brick grab comprising a frame, gripping jaws pivotally supported bythe frame, a lifting head for supporting the grab, means connectedbetween the lifting head and gripping jaws whereby shifting of the headtowards the jaws causes them to open and shifting of the head away fromthe jaws causes them to close, guide means comprising a tube supportedby the frame, and a shaft supported by the lifting head and disposed inand shiftable relative to the tube, said tube and shaft having aperturestherein which are in registry when the head is in lowered position andthe jaws are open, a channel member disposed transversely of the frameadjacent the lower portion of the tube, a plate positioned in thechannel member and having an opening to receive the tube, said openingbeing relatively elongated so that the plate can shift longitudinallywith respect to the tube, a pair of rods secured to the plate andextending through the channel member whereby the plate may be shifted,and a locking pin extending a portion of the distance across the openingin the plate and positioned so that it may be projected through theapertures in the tube and shaft when they are in registry so as to lockthe jaws in open position.

2. A brick grab as specified in claim 1 in which the locking pin isintegral with one of the rods secured to the plate.

3. A brick grab as specified in claim 1 in which the rods extend inopposite directions to opposite sides of the frame and have operatinghandles formed at the ends thereof.

4. A brick grab comprising a frame, gripping jaws comprising a pair ofconfronting bell cranks pivoted to opposite sides of the frame, saidbell cranks having downwardly depending gripping arms and horizontaloperating arms extending substantially across the frame, a lifting head,and means connecting the lifting head and bell cranks whereby shiftingof the head towards the frame opens the jaws and shifting of the headaway from the frame closes the jaws, said means comprising a pair ofbrackets pivotally mounted on opposite sides of the frame, a pair oflevers pivoted to the brackets and extending to adjacent the center ofthe frame, a link pivotally connected between the inner ends of thelevers and the lifting head, and links connected between the ends of theoperating arms of the bell cranks and the said levers adjacent thepoints of connection with the brackets.

5. A brick grab as specified in claim 4 in which interengaging guidemeans are supported on the frame and lifting head adjacent theapproximate center of gravity of the brick grab.

JOHN P. CALLAGHAN.

